Vapor Lock

[Logan]

I usually do not notice a hesitation, although there is sometimes a slight hesitation when I am accelerating hard at higher speeds, or when the engine is under a higher load, e.g. going up a hill.  I was chalking this up to a possible electrical problem (I got some advice on a distributor wire in another post).  But this is quite rare.  Normally it accelerates fine.

[Fid]

The water bottle never worked for me but it may depend on how hot it is and how hot the pump got. Once it vapor locked in my driveway (on a 90 degree day) and I sprayed the pump with a hose for a while and I still couldn't start it till I dumped some gas down the carb.  The real problem was it had an AC type pump which was made in Mexico - junk!  The pump itself leaked and spewed gasoline out the bottom diaphram when the engine was running and I think that was more of a problem than anything else.  Weas and I discovered that and then analyzed that high-quality Mexican made pump and found the bottom cover did not seat level and wobbled on the center divider between the inlet and check valve so that pump was sucking as much air as it was gasoline and spewing as much gasoline as it was delivering it to the carb.  A NOS replacement, AC pump cured it.  I drove my niece and her new husband around on their 80+ degree wedding day two years ago, made several short stops and NO problems of any kind. Of course, I still made sure the OD cable was out when starting up after those stops but there were no problems and as far as I know Weas has had none since.

[kaiserfrazerlibrary]

A lot of the new-looking pumps are in fact rebuilts even if they come in the original packaging.  According to George Buchinger who was in the parts business many years ago, when he was trying to stock fuel pumps he always went for the Carter version rather than AC.  He noted back in the 1960's and early 1970's that either new or rebuilt, the Carters lasted many times longer than the AC, and to him that justified the extra cost on Carter product.

Another factor to note on the pump side of the problem is the material used for the seals and the diaphragm.  A new pump in the box could have been build a long time ago and have the materials in it that alcohol based fuel (even the 10% mix type) attacks as a corrosive.

[Fid]

That's one of the reasons why the Carter pumps are now so hard to find. I've had both apart and I can see how the Carter pumps are more reliable and work better.

[AZ_HJ]

A good source for information, rebuild kits, and rebuild service on fuel pumps is 'Then and Now Automotive'.

http://maritimedragracing.com/antique_auto_parts_cellar.htm

They may not the cheapest supplier, but sometime you get what you pay for.

I have used them to rebuild my double action fuel pump (Carter) for my 6 cy '51 Henry J. I was pleased with price and turnaround time.

I have also recommended them to other club members for repair kits and they have been satisfied.

[Fid]

I've rebuilt two Carter pumps using their kits Mark. They work great. The Henry Js never vapor locked but they did wear out fuel pump diaphrams due to sitting in salvage yards for years.

[AZ_HJ]

Then and Now Automotive states the following concerning material used for thier Fuel Pump Kits:

"Our kits contain all the parts usually needed to repair an old, tired pump. Diaphragms, gaskets, seals and valves are all new fresh stock of materials intended for use with today's fuels, including fuel with alcohol content.

Our diaphragms are made of fabric reinforced Buna-N Nitrile rubber- the correct choice of the more than 400 different varieties of synthetic rubber made today. It is the one, single, correct, material for use with today's fuels.

We've seen our kits in service after 40,000 miles and 10 years of driving and they show very little ageing"

[Logan]

I wrote a lot of entries on a previous post about intermittent cutting out problems, thinking it was an electical issue.  Now that I think back on it almost all of them happened when the car was 1) hot, 2) accelerating up hill and 3) had sat at a stop light for a minute.  It happened again today (but not seriously, of course: it recovered) and I am more and more convinced that this is vapor lock, not an electrical issue.

[kaiserfrazerlibrary]

When I first encountered engine shut-off, I thought the coil got hot and opened due to thermal transfer.  I then found out that my temp sensor was bad and the gage never got past the "normal" half-way mark.  A new sender and I noted the overheating.  Since then I periodically checked the gage against a thermometer check of the radiator tank.  Not scientific or very accurate, but I could tell if the sender appeared to be working and the gage provided a generally accurate report.

[Kenn Evans II]

I have had the same problem on my 49, I took a stainless steel brake line 3/8 inch diameter from NAPA, and put it on a tubing binder and made it into a coil and I took a plastic coffee can and rerouted the fuel line to come from the fuel pump into this coiled tube and back out and it sits inside of the coffee can and when I get ready to putt around I fill the coffee can with water and sometimes ice and it has eliminated my roadside stalls. This might help,  the fuel line and the tubing was pretty cheap. I also put in an inline split fuel filter just before the carb and ran a line back to the tank, this has kept the fuel flowing and I routed it back to the top of the tank.  I copied the reroute off of my 73 Lincoln and I have only been stuck when I ran out of gas.